The invention relates to pump assemblies for providing high pressure oil to internal combustion engines. The high pressure oil may be used to actuate solenoid controlled hydraulic fuel injectors, solenoid controlled hydraulic intake and exhaust valves, or both injectors and valves.
Conventional vee-type diesel engines using HEUI fuel injectors mounted on a high-pressure swash plate pump in a chamber located in the vee recess between the cylinder banks. A cover closing the top of the chamber, extended over the pump. An injection pressure regulator (IPR) valve was mounted on the top of the cover. The passages extending between the pump and the valve passed through the cover and included a high-pressure passage which delivered high-pressure oil from the pump to the IPR valve, and a drain passage from the IPR valve. The IPR valve was mounted above the cover to facilitate servicing of the valve and permit routing the electrical leads for the valve solenoid outside the chamber.
Location of the pump in pump within the chamber under a cover and with an IPR valve mounted on the outside of the cover caused a number of problems. It was necessary to connect all of the passages extending through the cover to the pump and to the cover. High-pressure connections were required for the high-pressure passage extending from the pump to the bottom of the cover. The passage and the connections had to be sufficiently strong to withstand the high output pressure of the pump. This arrangement was undesirably expensive because of the cost of the high-pressure pipe and high pressure connections.
The cover had to be sufficiently strong and massive to withstand the output pressure of the pump. A high-pressure conduit extending from the pump to t h e bottom of the cover and the high-pressure connections at both ends of the conduit were required and increased the cost of the engine.
Accordingly, there is a need for an improved high-pressure pump assembly for internal combustion engines with hydraulically actuated devices where the assembly includes a pump located in a chamber under a lightweight cover and with a solenoid actuated pressure regulator valve located outside of the cover. The passage leading from the pump to the valve should withstand the high-pressure pump output without the need for a high-pressure conduit and connections.
The invention is an improved pump assembly particularly useful in a vee-type internal combustion engine with either HEUI fuel injection systems or solenoid controlled, hydraulically actuated intake and exhaust valves or both. The pump assembly includes a strong metal body capable of withstanding high pump output pressures. A high-pressure pump is provided in an inner portion of the body, a solenoid controlled pressure regulator valve is mounted on an outer portion of the body and a circumferential mounting flange is provided between the inner and outer portions of the body.
The pump assembly body is manufactured from high strength cast iron capable of withstanding high-pressure and includes a high-pressure output passage extending from the pump up through the body past the flange to the pressure regulator valve mounted on the outer portion of the body, above the cover. The assembly does not use a high-pressure connecting conduit and connections joining the conduit to the pump and to the cover.
The pump assembly body is manufactured from high strength cast iron capable of withstanding high pressure and includes a high pressure output passage extending from the pump up through the body past the flange to the pressure regulator valve mounted on the outer portion of the body, above the cover. The assembly does not use a high pressure connecting conduit and connections joining the conduit to the pump and to the cover.